这条高速公路上总是交通拥堵。

There is always traffic ___congestion on this highway.

鼻塞是感冒时的常见症状。

Nasal ___congestion is a common symptom when you have a cold.

大城市的交通拥堵是一个需要紧急解决方案的问题。

The traffic ___congestion in major cities is a problem that needs urgent solutions.